A deadly parasite, faulty sewage systems, and the sisters fighting for their small US community

When the letter arrived with the logo of a noted university in the corner, Veronica Reyes Ibarra expected good news. She called her boyfriend, her mom and her sisters over: “You guys, look what I got, I think it’s a scholarship.”

But as she scanned the page, she suddenly wasn’t sure she had the courage to read it out to them.

“Using a research diagnostic blood test,” the letter read, “we have determined that you may have been infected with a parasite.” The letter advised Reyes Ibarra to seek medical treatment.

Fifteen other residents of the tiny テキサス community where Reyes Ibarra lives received the same test result, after dozens gave blood and stool samples for an academic study. They ranged from a woman who was pregnant to a two-year-old child.

The intestinal parasite is known by its scientific name, Strongyloides (pronounced stron-ji-LOY-dees). It inhabits the guts of humans and other animals, and its larvae are excreted during defecation. If the larvae are able to contaminate soil – for instance, because of a sewage leak – they can survive for up to three weeks. In one common infection pathway, they can burrow through the skin of a person walking barefoot, entering the bloodstream, then the lungs, and ascend the windpipe, where they are coughed up and then swallowed.

Strongyloides can survive undetected in humans for decades, producing generation after generation. But at certain moments – such as when the host is taking steroids – they can become deadly.

After the letters went out, a scientific paper was published about Reyes Ibarra’s neighborhood as part of the same research project. But the parasite infections in her area have stayed under the radar, in part because the researchers preserved the town’s anonymity, identifying it as “Community A”.

Now Reyes Ibarra and her sister, モニカ, are sharing their story, as are other of their neighbors. They say no one with the ability to help is paying attention to their plight, and there has been no systematic attempt to eliminate the Strongyloides.

The researchers argue that this cluster is linked to one crucial, but often overlooked, aspect of intense US poverty: despite their best efforts, residents are subject to terrible sanitary system failures.

“I feel like everyone has passed the buck on this neighborhood because it’s low-income, it’s primarily Hispanic, immigrants,” said Monica. If the parasites had been found “in any other neighborhood, even just across the county line where there are people of other races, there would be an uproar: ‘how dare you keep us living in these conditions, how are children potentially exposed to harmful parasites that are only found in other developing countries.’ That would be unheard of. And it’s normal here. No one cares, basically.

Their community is named Rancho Vista, located less than an hour from the Texas capitol in Austin. It comprises about 400 homes on a small number of streets, and many of its inhabitants are Mexican Americans or immigrants from Mexico. Often they work in lower-paying fields like construction or groundskeeping, juggling multiple jobs, and have built their lives from the ground up in Rancho Vista, sometimes literally.

Yet residents say that despite the taxes they pay, they struggle with packs of stray dogs, which may themselves play a role in the parasite life cycle, and windblown swirls of trash. Sometimes the smell of sewage wafts in the breeze.

“It feels like we’re screaming into a void and no one is listening,” Monica said.

The sisters were born in Aguascalientes, メキシコ, but moved with their parents to Rancho Vista when they were little. They went to school in a nearby town and were bullied for living somewhere so downtrodden. Walking to the school bus on dark roads lacking streetlights, she and her friends made sure to carry sticks or rocks in case a stray dog became aggressive, Veronica recalled.

Today Veronica, 25, is studying for a master’s in public administration. モニカ, 28, recently passed the bar exam. But the conditions in Rancho Vista are the same ones the sisters have seen their whole lives. Veronica added: “This is literally the reality we live … it’s crazy.”

Rancho Vista emerged in the mid-1980s, when a developer parcelled the land. A few residents described buying a half-acre for just over $10,000, and they lived in mobile or modular homes, or built structures with their own hands. It was “a little oasis for immigrant families”, said Monica. 早い段階で, coyotes could be heard howling at night, and it still has a verdant, peaceful feel.

Yet for some it is a rural poverty trap. 一方では, because it is located outside any particular city – it is, in official terms, “unincorporated” – there are fewer regulations, and residents are freer to do renovations without inspections, 例えば. 一方で, they also lack services that most Americans take for granted.

There is no official garbage collection, nor are there sidewalks. And there are no sewer lines. 代わりに, the homes have ageing individual sewer systems in which effluent from toilets, sinks, showers and appliances is pumped into an underground tank next to the home. After some biodegradation in the tank, liquid is allowed to percolate into the ground as a kind of rudimentary sewage treatment.

より多い 20% of Americans have these septic systems, as they are known, including the very richest, such as those who live in the Hamptons area of Long Island. In lower-income areas they can present a challenge: they occasionally need to be pumped out, and otherwise maintained, shifting the burden for an essential service on to a financially stretched resident. The soil in Rancho Vista is mostly not considered compatible with septic systems in the first place, because it is not permeable enough and can cause the systems to clog.

Ask people in Rancho Vista about their problems, and many will tell you about the sewage.

“I am embarrassed when people come because it smells and stinks,」とある居住者は言った, who asked only to be identified by her last name, Perez. She tries to avoid using too much water to prevent sewage overflows.

Another inhabitant, Aide Barrera, 59, said her toilet sometimes does not flush, and to relieve herself, she has to go to a friend’s house or a restaurant. To prevent overburdening the temperamental septic system, the water from her shower, kitchen sink and washing machine are simply piped straight out to her back lawn.

Not having a functional toilet was particularly difficult when Barrera was raising her kids. “Thank God they understood they had to study to leave this place.” She could get the system fixed, but has been told it will cost $17,000. And “$17,000 is what I make in a year.”

The scientist whom some residents came to know as the “parasite lady”, and who led the Strongyloides study, arrived in 2017.

Rachael Singer was a doctoral student at the University of Texas at Austin who had previously performed parasite surveys in Nicaragua. She learned of Rancho Vista and its sewage problems through colleagues and decided to investigate. Along with a team, she canvassed door to door, winning residents’ trust and obtaining dozens of blood and stool samples.

“Knowing America has a history of [parasitic] infections”, Singer said, it seemed quite plausible that parasites would be found in a “region with failing sanitation infrastructure”.

Intestinal parasites were once presumed to be established across the US south. 20世紀初頭, rates of hookworm, which is transmitted through the soil like Strongyloides, だった higher than 75% in Alabama and almost two-thirds in Georgia. Widespread surveillance and eradication programs, and the spread of proper sanitation systems, were thought to have wiped them out. Surveillance largely ceased, even though a recent paper showed that nearly half a million US households lack indoor plumbing.

Yet in recent years, more than one-third of residents in an Alabama community with sanitation breakdowns tested positive for hookworm. In an ongoing study, Rojelio Mejia, the prominent parasitologist who co-authored the Rancho Vista paper, has discovered high rates of Toxocara, which is spread in dog and cat feces, in soil and wastewater samples from poor communities across five southern states.

Strongyloides is considered one of the more neglected of the soil-transmitted parasites. Doctors with no training in tropical medicine might fail to recognize it, and are not mandated to report its discovery to state authorities. まだ more than half a billion people around the world are estimated to be infected, and in the US it has been detected in places as varied as Appalachia そして Los Angeles county, とで organ transplant candidates, patients with mental disabilities そして Vietnam veterans decades after they served.

Although it can be symptomless, Strongyloides is the deadliest of soil-transmitted parasites. If an infected person takes immune-suppressing drugs such as steroids or chemotherapeutics, or has a lowered immune system because of a disease like leukemia, the worm can rapidly multiply throughout the body and cause death.

In Rancho Vista, インクルード 16 positive blood tests from a group of 97 residents is the highest percentage of positive blood samples found in a non-refugee population in the US, according to Singer, though the sample is relatively small. (A positive blood test can also occur in someone who was previously infected but no longer is.)

Singer believes that Strongyloides is being transmitted locally in Rancho Vista, via the soil on which the community is built. In support of this she cites the fact that an infant who has never traveled elsewhere was diagnosed. Singer also hypothesizes that the stray dogs may be part of the transmission loop if their own infected waste is polluting the environment.

The possibility remains that residents who tested positive acquired the parasite outside Rancho Vista, only to be tested while living in the same place. Outside experts say Singer’s conclusions are plausible – but not all are as certain as she is.

The results indicate that some residents “probably acquired the infection in their community”, said Thomas Nutman, chief of the laboratory of parasitic diseases at the National Institute of Allergy and Infectious Diseases, who was not involved with the original research. “And I think the important piece is the only likely way that this could happen is for fecal contamination of the environment.”

Another Strongyloides expert expressed caution because the Rancho Vista researchers do not have lifelong travel histories for all the residents who were tested, and so do not know if they previously visited a place where Strongyloides is prevalent. “Overall it’s suggestive there could be locally acquired infection in Texas, but not quite as strong as I’d like to see in order to make that conclusion,” said Curtis Croker, an epidemiologist with the acute communicable disease control program at the Los Angeles county department of public health.

Singer advised residents to take the letters apprising them of their test results to their doctors. But she heard from several residents that they were never prescribed the treatment: a single dose of the drug ivermectin.

Veronica received the medicine. She and Monica believe that the best solution for their community is to be hooked up to a municipal sewer system, possibly in the city of San Marcos, whose nearest lines are a mile away. This would prevent Strongyloides larvae, if they are present, from reaching the soil, where they can only survive for up to three weeks. Fixing the existing septic tanks would merely be a temporary remedy, 彼らが言う, because sewage leaks could still occur.

Yet according to San Marcos mayor Jane Hughson, “there’s no legal responsibility because [Rancho Vista] is just an entity outside the city.” Rancho Vista can’t even apply to become part of San Marcos because their boundaries are not contiguous, 彼女は言いました. “They’re kind of in a no man’s land out there. It’s not good and it’s sad – but the city can’t fix anything.”

The Guadalupe county official representing Rancho Vista did not respond to a list of questions from the Guardian about the situation or how to resolve it.

The Reyes Ibarra sisters feel that many of their efforts have to come to nothing, and they occasionally feel hopeless.

“Who do we talk to?” Monica wondered out loud, as she sat with Veronica recently in their kitchen in Rancho Vista.

“It’s a little frustrating and a little embarrassing because I’m like, we should know who to talk to," 彼女は言いました. “Then I think: unlike some of our neighbors, we can speak English, we have some contacts, we have more schooling than a lot of people in our neighborhood, and if we can’t figure it out, nothing is ever going to be done if we stop.”

Their father, Antonio Reyes, 53, says that one of his greatest joys in Rancho Vista has been to watch his girls grow up – they now live in a handsome home that he helped to build himself in the community. He says that although he was aware of the sewage contamination, he had sought to keep them safe from it. In Rancho Vista, “it’s like living in another country as opposed to the United States," 彼は言った.